Influence of Parathyroidectomy on Kidney Graft Function in Secondary and Tertiary Hyperparathyroidism

Surgical outcomes of parathyroidectomy for pre-kidney transplantation versus post-kidney transplantation patients

BACKGROUND

Hyperparathyroidism (HPT) is common in end-stage kidney disease and resolves in less than half of kidney transplant (KT) recipients. The ideal timing of parathyroidectomy (PTX), before or after KT, remains unclear. We sought to understand differences in morbidity and mortality after PTX pre-KT and post-KT.

METHODS

We identified adult patients who underwent PTX pre-KT or post-KT between 2012 and 2021 utilizing the National Surgical Quality Improvement Program database. Demographics, clinical characteristics, morbidity, and mortality were compared. Adjusted logistic regression with propensity score weighting assessed odds of 30-day composite morbidity, major adverse cardiovascular events (MACE), readmission, and mortality.

RESULTS

We identified 1972 patients who underwent PTX pre-KT and 541 patients who underwent PTX post-KT. Post-KT HPT patients were older (mean age 53.9 v 48.2 and p < 0.01) and more commonly White (45.3% v 32.3% and p < 0.01) and diabetic (30.0% v 18.5% and p < 0.01). In comparison, pre-KT HPT patients were more commonly Black (53.2% v 30.1%), had American Society of Anesthesiologists (ASA) class 3-4 (98.0% v 89.6% and p < 0.01), chronic obstructive pulmonary disease (4.2% v 1.5% and p < 0.01), and congestive heart failure (4.4% v 1.1% and p < 0.01). After adjusting for confounders, patients pre-KT had 1.72-fold increased odds of morbidity (95% confidence interval [CI]: 1.13-2.61), 8.39-fold increased odds of MACE (95% CI: 1.13-62.18), and 2.07-fold increased odds of readmission (95% CI: 1.38-3.10). There was no difference in mortality or risk of infections.

CONCLUSIONS

Patients who underwent PTX prior to KT were at significantly increased risk for 30-day morbidity and MACE, but no different odds of mortality compared to PTX after KT. This can help inform decision-making regarding timing of PTX in patients with HPT.

Effect of Parathyroidectomy After Renal Transplantation on Grafted Kidney Function Within One Year: A Meta-Analysis

OBJECTIVE

Secondary hyperparathyroidism (sHPT) is a common symptom of chronic kidney disease (CKD), and at the time of transplantation, more than two-thirds of patients with end-stage renal disease have secondary hyperparathyroidism. After kidney transplantation, parathyroid function is normalized in some kidney transplant recipients, but up to 50% of kidney transplant recipients develop tertiary hyperparathyroidism (tHPT) 1 year after kidney transplantation. The effect of parathyroidectomy on the grafts is currently unclear; thus, we conducted a meta-analysis of relevant studies to evaluate changes in graft function 1 year after parathyroidectomy, aiming to assess the procedure's safety in renal transplant recipients.

METHODS

A thorough exploration was conducted across Embase, PubMed, Web of Science, and the Cochrane Library databases to gather pertinent literature spanning from January 1, 2000, to December 31, 2023. The search criteria encompassed terms such as "kidney transplantation," "parathyroidectomy," and "hyperparathyroidism."

RESULTS

Twelve studies were scrutinized to assess alterations in graft functionality at 1, 3, 6, and 12 months postparathyroidectomy. The meta-analysis unveiled a notable decline in overall glomerular filtration rate and a concurrent elevation in serum creatinine 1 year postparathyroidectomy, signifying an impairment in graft function compared to the preoperative phase. Significant heterogeneity was observed among the studies.

CONCLUSION

Following parathyroidectomy in renal transplant recipients 1 year postsurgery, calcium and parathyroid hormone levels normalized. Nonetheless, there was evident impairment in graft function and an elevated risk of graft loss. Hence, the safety of parathyroidectomy in patients with secondary hyperparathyroidism postrenal transplantation necessitates meticulous consideration.

Does race impact outcomes after parathyroidectomy for secondary and tertiary hyperparathyroidism?

BACKGROUND

Racial disparities in care exist for diseases with heterogeneous treatment guidelines. The impact of these disparities on outcomes after parathyroidectomy for secondary(2HPT) and tertiary hyperparathyroidism(3HPT) was explored.

METHODS

The 2015-2019 NSQIP datasets were used. Patients who underwent parathyroidectomy for 2HPT and 3HPT were identified and analyzed separately. Patients were stratified by race (white vs. non-white); demographics, comorbidities, and outcomes were compared. Studied outcomes included 30-day morbidity, mortality, unplanned reoperation, readmission, and postoperative length of stay(LOS).

RESULTS

There were 1,150 patients with 2HPT and 262 with 3HPT. For 2HPT, 65.5% were non-white; morbidity, reoperation, and prolonged LOS(>3days) occurred disproportionately more often in non-white patients. Non-white race was independently associated with morbidity; higher ASA class and alkaline phosphatase levels were associated with prolonged LOS. For 3HPT, 53.1% were non-white; a prolonged LOS(>1day) occurred disproportionately more often in non-white patients. Higher alkaline phosphatase levels were independently associated with prolonged LOS.

CONCLUSION

Race and markers of advanced disease negatively impact outcomes after parathyroidectomy for 2HPT and 3HPT. Attention to racial disparities and earlier referral may positively impact outcomes.

Timing of parathyroidectomy for kidney transplant patients with secondary hyperparathyroidism: A practical overview

Kidney transplantation remains the best treatment for patients with end-stage kidney disease, and it could partially mitigate systemic disorders of mineral and bone metabolism caused by secondary hyperparathyroidism. However, persistent hyperparathyroidism is still observed in 30-60% of patients 1 year after kidney transplantation, leading to impairment of allograft function and a disturbance of mineral metabolism. The timing of parathyroidectomy varies among transplant centers because the possible negative effects of parathyroidectomy on allograft outcomes are still unclear. This review provides a comprehensive and detailed overview of the natural course of hyperparathyroidism following kidney transplantation and the effects of the timing and extent of parathyroidectomy on allograft function. It aims to provide useful information for surgeons to propose an appropriate intervention strategy to break the vicious cycle of post-kidney transplantation hyperparathyroidism and deterioration of allograft function.

Systematic Review of the Treatment of Persistent Hyperparathyroidism Following Kidney Transplantation

Chronic kidney disease-mineral and bone disorder is one of the complications associated with chronic kidney disease. About 10-50% of patients following kidney transplantation have persistent hyperparathyroidism. Hypercalcaemic hyperparathyroidism has a negative impact on the kidney transplant outcome; therefore, it requires treatment. The data regarding the treatment of persistent hyperparathyroidism provided in scientific publications are divergent and contradictory. Therefore, the aim of our systematic review was to evaluate the efficacy of persistent hyperparathyroidism treatment in patients following kidney transplantation. The Cochrane, PubMed, and Scopus databases were browsed independently by two authors. The search strategy included controlled vocabulary and keywords. The effectiveness of calcitriol, paricalcitol, cinacalcet, and parathyroidectomy was compared and analysed. The mean calcium and parathormone (PTH) concentrations per patient in the group of paricalcitol increased by 1.27% and decreased by 35.14% (n = 248); in the group of cinacalcet decreased by 12.09% and 32.16% (n = 368); and in the group of parathyroidectomy decreased by 19.06% and 86.49% (n = 15) at the end of the study compared to the baseline (n = 244, n = 342 and n = 15), respectively. Paricalcitol, cinacalcet, and parathyroidectomy decreased the intact PTH level. Cinacalcet and parathyroidectomy lowered calcium levels in renal transplant patients with hypercalcaemia. Conversely, paricalcitol increased the serum calcium concentration. Cinacalcet seems to be a good candidate in the treatment of post-transplant hyperparathyroidism.

Association Between Treatment of Secondary Hyperparathyroidism and Posttransplant Outcomes

BACKGROUND

Secondary hyperparathyroidism (SHPT) affects nearly all patients on maintenance dialysis therapy. SHPT treatment options have considerably evolved over the past 2 decades but vary in degree of improvement in SHPT. Therefore, we hypothesize that the risks of adverse outcomes after kidney transplantation (KT) may differ by SHPT treatment.

METHODS

Using the Scientific Registry of Transplant Recipients and Medicare claims data, we identified 5094 adults (age ≥18 y) treated with cinacalcet or parathyroidectomy for SHPT before receiving KT between 2007 and 2016. We quantified the association between SHPT treatment and delayed graft function and acute rejection using adjusted logistic models and tertiary hyperparathyroidism (THPT), graft failure, and death using adjusted Cox proportional hazards; we tested whether these associations differed by patient characteristics.

RESULTS

Of 5094 KT recipients who were treated for SHPT while on dialysis, 228 (4.5%) underwent parathyroidectomy, and 4866 (95.5%) received cinacalcet. There was no association between treatment of SHPT and posttransplant delayed graft function, graft failure, or death. However, compared with patients treated with cinacalcet, those treated with parathyroidectomy had a lower risk of developing THPT (adjusted hazard ratio, 0.56; 95% confidence interval, 0.35-0.89) post-KT. Furthermore, this risk differed by dialysis vintage (Pinteraction = 0.039). Among patients on maintenance dialysis therapy for ≥3 y before KT (n = 3477, 68.3%), the risk of developing THPT was lower when treated with parathyroidectomy (adjusted hazard ratio, 0.43; 95% confidence interval, 0.24-0.79).

CONCLUSIONS

Parathyroidectomy should be considered as treatment for SHPT, especially in KT candidates on maintenance dialysis for ≥3 y. Additionally, patients treated with cinacalcet for SHPT should undergo close surveillance for development of tertiary hyperparathyroidism post-KT.